Sàng lọc • Sàng lọc loại bỏ tính toán • Sàng lọc Pit Công suất tính toán Grit diệt • Tính toán diệt Grit • Grit kênh vận tốc tính toán Giai đoạn ban đầu của điều trị trong quá trình xử lý nước thải (sau đây bộ sưu tập và chảy đến bơm) là sơ chế. Quá trình lựa chọn thường là dựa trên các đặc điểm dự kiến của dòng chảy đến. Chảy đến thô vào nhà máy xử lý có thể chứa nhiều loại vật liệu (thùng rác), và sơ chế bảo vệ các thiết bị nhà máy. | Part III Wastewater Math Concepts 2004 by CRC Press LLC 22 Preliminary Treatment Calculations TOPICS Screening Screening Removal Calculations Screening Pit Capacity Calculations Grit Removal Grit Removal Calculations Grit Channel Velocity Calculations The initial stage of treatment in the wastewater treatment process following collection and influent pumping is preliminary treatment. Process selection normally is based upon the expected characteristics of the influent flow. Raw influent entering the treatment plant may contain many kinds of materials trash and preliminary treatment protects downstream plant equipment by removing these materials which could cause clogs jams or excessive wear in plant machinery. In addition the removal of various materials at the beginning of the treatment train saves valuable space within the treatment plant. Two of the processes used in preliminary treatment include screening and grit removal however preliminary treatment may also include other processes each designed to remove a specific type of material that presents a potential problem for downstream unit treatment processes. These processes include shredding flow measurement preaeration chemical addition and flow equalization. Except in extreme cases plant design will not include all of these items. In this chapter we focus on and describe typical calculations used in two of these processes screening and grit removal. SCREENING Screening removes large solids such as rags cans rocks branches leaves and roots from the flow before the flow moves on to downstream processes. Screening Removal Calculations Wastewater operators responsible for screenings disposal are typically required to keep a record of the amount of screenings removed from the flow. To keep and maintain accurate screening records the volume of screenings withdrawn must be determined. Two methods are commonly used to calculate the volume of screenings withdrawn screenings cu ft Screenings removed cu ft day ------- .
